Nguyen Binh T, Inui Koji, Hoshiyama Minoru, Nakata Hiroki, Kakigi Ryusuke
Department of Integrative Physiology, National Institute for Physiological Sciences, Okazaki 444-8585, Japan.
Clin Neurophysiol. 2005 Jun;116(6):1247-53. doi: 10.1016/j.clinph.2005.01.018. Epub 2005 Mar 28.
To investigate the somatotopic organization of the facial skin area in the secondary somatosensory cortex (SII) in humans.
Somatosensory evoked magnetic fields following air-puff stimulation of 5 body sites, the foot, the lip and 3 points of the facial skin (forehead, cheek and mandibular angle point), were recorded. We focused on activities in SII following stimulation of these 5 sites and compared dipole locations among them.
There was a clear somatotopic organization in SII with lip in the most lateral area, foot in the most medial area and face in an intermediate area close to the lip area. However, there was no significant difference of dipole localization in SII among the 3 areas of facial skin, similar to the overlapped somatotopic organization of facial skin areas in the primary somatosensory cortex in our previous study.
The facial skin areas are considered to occupy a small area in SII with insufficient spatial separation to differentiate each area of facial skin even using magnetoencephalography which has a high spatial resolution.
This is the first systematic study of the activated regions in SII following stimulation of the facial skin.
研究人类次级体感皮层（SII）中面部皮肤区域的躯体定位组织。
记录对足部、唇部以及面部皮肤的3个点（额头、脸颊和下颌角点）这5个身体部位进行吹气刺激后产生的体感诱发磁场。我们重点关注对这5个部位进行刺激后SII中的活动情况，并比较它们之间的偶极子位置。
SII中存在明显的躯体定位组织，唇部位于最外侧区域，足部位于最内侧区域，面部位于靠近唇部区域的中间区域。然而，面部皮肤的3个区域在SII中的偶极子定位没有显著差异，这与我们之前研究中初级体感皮层中面部皮肤区域重叠的躯体定位组织情况类似。
面部皮肤区域在SII中所占面积较小，即使使用具有高空间分辨率的脑磁图也没有足够的空间分离来区分面部皮肤的各个区域。
这是首次对面部皮肤刺激后SII中的激活区域进行的系统研究。
